I had to read twice to understand 2 things...
One the time between their break up and Jing Xiu marriage... I had understand firstly that she had come back before they are a couple but it was after that (3 years later) and 2 years before JX marriage with the man...
Another thing in he her previous life... When Ji YouYan tried to stop JX's marriage in reality JY already been dead, it was only her soul trying to stop it... I because of that se passed through JY ad made that face because she got the news in that day... And that time...